Illness or over-training you decide

I'm going with illness i have been doing a fair amount of training but no more than I've done in the past, i missed a couple of races with cold like symptoms which i just could not shift, i had the obligatory mild swine flu that every 'man' has had, more annoyingly i missed the London to Brighton when i felt fine during the week but by the time the weekend and the race came i felt appalling, it was at this point that i decide to take 3 weeks off from any running/cycling just doing a little light walking, do i feel any better, no not really but I'm bored so have decided to have a go at the Caesar's 50, i have a busy few weeks lined up after the Caesars 50, i have a weekend of navigation training in Brecons followed by a week in Toronto and the Toronto marathon, then hopefully at the end of October i have a week away somewhere warm to do some swim training.....